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'89 Mini City To 'mk1 Cooper S'


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#316 johnR

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Posted 30 April 2019 - 06:10 PM

I've sprayed the brake servo - then scratched it after fitting by leaning on the oil pressure pipe which runs across it. It'll do for now - I'll get it powdercoated when I have time. Brakes are connected with new master cylinder as the old one (original) had leaked into the servo.
I rubbed down the 2nd head steady bracket but it keeps reacting when I spray it - I think l'll dump the aerosol of gloss black - it's been nothing but trouble with everything I've painted with it. I'll leave the steady off for now and have it powdercoated as well or get a new can of gloss.
Carbs bolted on with a skim of RTV either side of the main gasket around the inlet ports, pipes and cables connected (looks like the choke will need shortening!). Power connected to the windscreen washer motor.
Now I need to connect the exhaust to the manifold and we should be ready to fire it up.
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#317 johnR

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Posted 02 May 2019 - 09:49 AM

I've now connected up the exhaust system, run and connected all the cables and there's good suction through the carbs. Will it start though? No. It occasionally fires, then revs to about 3k and dies. I've tried every degree of turn on the dizzy and added extra turns on the jets to a max of 2 1/2 turns open. Getting very fed up with it!

#318 iain1967s

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Posted 03 May 2019 - 02:27 AM

Try blocking off the servo pipe at the manifold. Maybe it’s sucking air.

#319 johnR

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Posted 03 May 2019 - 03:48 PM

Yes, I'll try that - might get all new gaskets for the carbs and spacers too although it does seem to be sucking through OK - anyone know what the suck rate should be before firing? I've got one of those snailshell type gauges.

#320 johnR

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Posted 06 May 2019 - 04:53 PM

Today we ascertained that the engine will run (roughly) if one carb mouth is covered. Getting nearer.



#321 johnR

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Posted 09 May 2019 - 03:23 PM

Still trying to track down the reason for excessive leaness - I took the exhaust and inlet manifolds off to compare flange thicknesses - only about 1mm difference which would be compensated for by the washer sloping either way but I ground them all to a closer tolerance while I had it all apart so I can rule out that possibility for a possible seal failure.   AH2 needles (currently M) and two new gaskets ordered.



#322 johnR

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Posted 11 May 2019 - 09:54 PM

One of the threads in one of the carb flanges that mount the air filter was shot so I ordered a UNC helicoil kit on Ebay that arrived yesterday. It was the first time I'd done one but found it was easy once I'd worked out to put the insert down over the mounting tool rather than trying to screw it in with the fitting tang uppermost!
Then the new needles and gaskets arrived so I punched the holes in the gaskets for the locating pins and made some small adjustments to the apertures although they were almost spot on as they came. One needle fitted and centred, the other to do.

#323 johnR

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Posted 12 May 2019 - 10:10 PM

2nd richer needle fitted and with the help of a local petrolhead recommended by a mechanic friend we adjusted one float height by shimming down the valve body with a copper washer. also found that one of the float valves was sticking with no obvious cause but it's now cleared. The combination of all three seems to have done the trick because it now starts and runs on partial choke so will adjust jets tomorrow and we should be good to go - finally!

#324 johnR

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Posted 13 May 2019 - 09:24 PM

Once again it sounds simple but rarely is! We spent three hours this evening tweaking the carbs and linkages to get smooth action but whilst it's showing signs of improvement it's fighting us all the way. In the end it overheated so we called it a night.

#325 johnR

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Posted 15 May 2019 - 09:38 PM

I've now richened it enough to start reasonably reliably although it still seems to be running quite hot and I'll soon run out of flats on the adjustment nuts - the temp gauge shows just above normal but then it boiled over - dodgy thermostat? Oil pressure still showing 100psi as well - sticking bypass valve? Then I ran out of petrol, this engine is definitely playing hard to get! Also need to bleed the clutch as selecting gears is difficult and there doesn't seem to be much pedal.



#326 johnR

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Posted 16 May 2019 - 02:53 PM

A better day today - I swapped the Cooper ball bearing type oil bypass valve back to the hollow slug type and pressure sits nicely at 75 psi so that's that sorted! Some more tweaking with advance and idle screws has achieved a reasonable idle although revs rise and fall a bit. I took it for a 100yard drive up the road and everything worked as it should - hopefully a milestone!
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#327 johnR

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Posted 22 May 2019 - 04:34 PM

Passed its MOT today but driving it there and back was not the most pleasant experience. It won't hold a low idle and although it runs Ok most of the time, occasionally it seems to go out of balance and shudders for a while. I'll try the richer needles (E2) I've ordered but if there's no joy there it's off to the experts or I'll miss the summer altogether!

#328 johnR

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Posted 23 May 2019 - 05:05 PM

Another coat of paint (the last one!) has gone on the headstay bracket and the underbonnet soundproofing kit has arrived from Newton.

It was a fairly good fit out of the box - I had to trim a couple of the panels that were a little large and cut some holes to clear the fixings for the bonnet strap. There wasn't enough glue to put some on the bonnet and on the back of the soundproofing as suggested in the instructions so I just glued the bonnet and put the two together. Should be OK, I'm doing it with the bonnet off so it doesn't need to be stuck on contact as it would if you were sticking it upsidedown. 

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#329 johnR

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Posted 25 May 2019 - 02:55 PM

The E2 needles arrived and were fitted, disappointingly with no discernable difference. the car still won't idle below 1500 rpm and if I drive it runs OK for a few hundred yards then carbs seem to go out of balance and bog down. I now give up and will book it in for professional help.

#330 imack

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Posted 25 May 2019 - 03:33 PM

Are you using a bmc leyland type manifold? Are the core plugs in either end of the manifold sealed properly?




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